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91.
Depth profiling analysis of wood samples using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was carried out to obtain information on the chemical changes caused by weathering. The test samples used for PAS measurements were tropical wood species, puspa (Schima wallichii Korth) and kapur (Dryobalanop lanceolata Burck), that were exposed outdoors for periods of 2–32 weeks. FTIR-PAS spectra of the weathered surfaces were recorded at various moving-mirror velocities in the range from 0.081 to 0.56cm/s (linear-scan method) to provide the depth profiling analysis. The band intensity of vibrations attributed to phenyl groups clearly decreased as weathering proceeded and demonstrated a tendency to be reduced with a decrease in the photoacoustic probing depth during relatively short weathering periods. The bands of C=O groups also exhibited remarkable spectral changes. The PAS spectra of the tropical wood changed considerably during the 32 weeks of weathering, and their spectral contours gradually approached that of pure cellulose (microcrystalline). It was noted that FTIR-PAS is very useful for depth profiling analysis of the wood surface in the early stages of deterioration.  相似文献   
92.
 Two Fourier transform infrared spectroscopic techniques, photoacoustic and diffuse reflectance spectroscopy, were utilized to explore the physical and chemical changes in wood caused by weathering. Five tropical wood species (albizia, kapur, mahoni, nangka, puspa) were exposed to natural weathering for various periods. The contents of extracts, phenolics, and Klason lignin in unexposed samples of these wood species were determined by chemical analysis. Infrared spectra of the weathered surfaces were recorded by the two techniques. The photoacoustic spectra exhibited rapid decomposition and elusion of wood constituents containing benzene rings in the region closest to the exposed surface. Line maps of infrared spectra in the vertical direction obtained by diffuse reflectance infrared microspectroscopy were consistent with the view that the additive effects of water and ultraviolet irradiation play an important role in destroying the lignin-hemicellulose matrix of the cell wall. The infrared spectroscopic techniques are available for the analysis of weathered wood. Received: October 22, 2001 / Accepted: February 20, 2002 Correspondence to:S. Yamauchi  相似文献   
93.
This report describes the pathological characterizations of a rare case of necrosis of the femoral head that was spontaneous, bilateral, avascular and nontraumatic. A 14-month-old beagle dog was presented with pain in the hind limbs. At necropsy, the articular surface in the bilateral femoral head was markedly irregular. There were no gross abnormalities other than in the hip joints. Microscopically, a wide range of trabecular bone necrosis localized in the subchondral area was observed in both femoral heads. In the right femoral head, fibrosis and proliferative vessels were noted in the subchondral area. The articular cartilage was thickened irregularly, but there was no evidence of cartilage necrosis. The bone marrow adjacent to the affected area showed severe depression. In the metaphysis, atrophic bone marrow, but not bone necrosis, was observed. This was a rare case of spontaneous necrosis of the femoral head in an experimental beagle dog.  相似文献   
94.
An eosinophilic substance (ES) is usually observed in the mouse nasal septum and increases in volume with aging. It has been described as amyloid in textbooks and one report. However, it has been described as "not amyloid" in other reports because there was a negative reaction to Congo red. In this study, the ES was investigated histopathologically and electron microscopically to determine whether it was amyloid or not. The ES was only observed at the interstitium of clear HE-stained nasal glands in the septum, in which 2 kinds of glands were present (dark and clear stained by HE). The volume of the ES was small in young mice and large in older ones. Neither nasal gland degeneration nor inflammation resulted, even if a large amount of the ES was observed. The ES reacted negatively to Congo red but was strongly positive to periodic acid-Schiff reaction with prior diastase treatment. In the electron microscope observation, the ES consisted of amorphous material and collagen, but no nonbranching fibrils. Similar amorphous material was also observed in the nasal gland epithelial cells and was connected to the material in the rough endoplasmic reticulum. The above-mentioned findings indicated that the ES was not amyloid and suggested the ES might consist of not only collagen but also complex carbohydrate, which was produced by the nasal gland epithelial cells.  相似文献   
95.
The aim of the present study was to investigate whether changes in body temperature are related to the ovarian cycle in elephants. Rectal, tongue or fecal temperature was measured for 2 Asian and 5 African elephants using an electric thermometer. Evaluation of ovarian cycles was based on the changes in serum or fecal progestin. The mean +/- SD values of the rectal, tongue, and fecal temperatures were 36.3 +/- 0.3 (2 Asian), 36.2 +/- 0.5 (1 African) and 36.5 +/- 0.3 C (4 African), respectively; the fecal temperature was the highest of the 3 temperatures (P<0.01). The longitudinal changes in body temperatures correlated with the ovarian cycle, with higher temperatures occurring during the luteal phase. The fecal temperatures of one acyclic African elephant did not change cyclically. These results suggest that measurement of body temperature can be used to easily evaluate the ovarian cyclicity of an individual animal, although it might not be able to determine the ovarian cycle length.  相似文献   
96.
Summary  Chromium(III), Cr(III) adsorption capacities of the leaves of 34 conifer species were examined. Among these, Ginkgo biloba, Taxus cuspidata, Cephalotaxus harringtonia var. nana, and Taxodiaceae and Cupressaceae spp. showed large capacities to adsorb Cr(III). The adsorption capacities of conifer leaves for Cr(III) (3.12–5.09 mg Cr g−1 adsorbent) compared favorably with those of commercial activated carbons (1.23–2.75 mg g−1). Factors affecting Cr(III) adsorption were studied using G. biloba leaves. The factors included solution pH, contact time, temperature, and the initial concentration of Cr(III). The amount of Cr(III) adsorbed on the adsorbent increased steadily with increasing pH in a pH range from 2 to 5, with increasing contact time, and with increasing temperature ranging 20 to 40 °C. The Cr(III) adsorption was also affected by the initial concentration of Cr(III) in the solution.  A linear relationship was observed between the amount of Cr(III) adsorbed and the equilibrium concentration of Cr(III) in the solution when graphed logarithmically. The maximum capacity of G. biloba leaves was 27.5 mg Cr g−1 adsorbent by column experiments. Received 13 January 1998  相似文献   
97.
The distribution of amyloid deposits was histopathologically and immunohistochemically examined in 25 cows aged 5 to 10 years that had been diagnosed with systemic AA amyloidosis. This examination revealed that amyloid deposits were also present in the hypophysis, ovary, uterus, mammary gland and skeletal muscle, in addition to the liver, kidney, spleen, pancreas, thyroid gland, adrenal gland, gastrointestinal mucosa, heart, lung and lymph nodes. The examined cows tended to have chronic inflammations, including chronic mastitis (six cases) or chronic pneumonia (four cases), which is thought of as a causative agent of AA amyloidosis. In contrast, five cases did not exhibit any chronic inflammation.  相似文献   
98.
The purpose of our publication is to widely communicate the pictures of spontaneous findings occurring in beagles. Spontaneous arteritis occurs commonly in beagles. Frequent sites of arteritis are the heart, spleen, pancreas, epididymis and spinal cord. Morphological similarities between spontaneous and drug-induced arterial lesions may cause confusion when evaluating vascular toxicity of chemicals such as vasodilating agents. Focal and minimal inflammatory lesions are occasionally seen in the lung and may be associated with aspiration of food particles or of unknown causes. A cystic change with copious mucin production occurs occasionally in the mucosal epithelium of the gall bladder. Nesidioblastosis is seen rarely in the pancreas of beagles. C-cell complex and lymphocytic thyroiditis are common thyroid lesions. Spontaneous focal hypospermatogenesis and lobular Sertoli-cell-only seminiferous tubules occurring frequently in beagles must be distinguished from drug-induced damage of the seminiferous tubules in toxicity studies. The morphological differences of the female genital system in each cycle need to be understood; therefore, we present the normal features of the cyclic changes of the female genital organs. Further, we provide more information on spontaneous findings in beagles for exact diagnoses in toxicity studies.  相似文献   
99.
One female newborn piglet showed prominent thickening of both forelimbs and died soon after birth. Histopathologically, thin and woven trabeculae of bone was extending out from the edge of cortical bone in the affected forelimbs, and diagnosed as congenital hyperostosis. The extent of radially proliferated trabeculae was most prominent in radioulna. Many round- to spindle-shaped cells were observed in periosteum, which were considered to be osteoblasts. Around the periosteum, the mesenchymal proliferation was extensive with abundant mucus, and cartilaginous metaplastic changes were observed mainly around the radioulna and humerus. Dilatation of vessels with fibrin deposition in vessel walls was often observed, which were considered to reflect the localized circulatory disturbance.  相似文献   
100.
Pituicytoma is an extremely rare neoplasm derived from pituicytes, which are glial cells in the posterior lobe of the pituitary gland. A malignant pituicytoma was found in the intracranial cavity of a 55-week-old male Sprague-Dawley rat. Macroscopically, the tumor was located on the sphenoid bone and involved the pituitary gland. The tumor was composed of sheets of fusiform cells with spindle- or pleomorphic-shaped nuclei and abundant eosinophilic cytoplasms. The cells were arranged in a whirling or irregular growth pattern. Some tumor cells were bizarre multinucleated giant cells with cytoplasmic eosinophilic hyaline droplets. Many tumor cells were strongly positive for vimentin and glial fibrillary acidic protein, and some cells were positive for ED-1 and S-100. These findings closely resembled those of a giant cell glioblastoma derived from the pituitary gland, suggesting anaplastic pituicytoma. From our review of the literature, we believe this is the first report of a spontaneous malignant pituicytoma in a rodent.  相似文献   
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